Property patterns ^{C# 8.0} are a very powerful feature, however matching properties within nested objects was verbose.

C# 10.0 simplifies this by allowing dot notation to match nested properties directly.

Code

Now

return analysis switch
{
    { MatchedRule.Action: "ignore" } => Action.Ignore,
    _ => Action.Block,
};

Before

return analysis switch
{
    { MatchedRule: { Action: "ignore" } } => Action.Ignore,
    _ => Action.Block,
};

Notes

• Reduces the need for deeply nested { Prop: { SubProp: value } } syntax
• Works with any pattern, not just constants, so you can use relational patterns, var captures, etc.

More information

• Specification
• C# Reference